Add ownership management to the MapLayerRegistry
Fix crash with render caching and feature blending combination
[Fix #7867] Fix field properties config dialog
[Fix #7892] Fields properties: Fix sorting by id (numeric)
Add relation manager ui

Conflicts:
	src/app/qgsprojectproperties.cpp
	src/ui/qgsprojectpropertiesbase.ui
Add relation edit type
Remove unneeded method
Singleton
Add editor widgets wrapper
Whatever
New attribute editor API
Further widgetfactory stuff
Add new editorwidget api v2
Move to editorwidgetsv2
Make sip bindings work
Further improvments
Wow, big changes
Save and read widget configuration to/from project file
Wow, this seems to be working!
Allow pre-created editor widgets (as happens when you provide your own ui file)